From one 2006 study to a research center: the history of Johns Hopkins psilocybin research

Johns Hopkins is where modern psilocybin research restarted in the United States. In 2000 its group became the first to win US regulatory approval to give psychedelics again to healthy volunteers who had never used them, and its 2006 paper is described by the university as having sparked a renewal of psychedelic research worldwide.

This page tells that story in order: the people, the main published studies with their designs and sample sizes, the 2019 center, and the criticisms. It describes research. It makes no claim that psilocybin treats anything and gives no doses.

How did Johns Hopkins psilocybin research begin?

It began with a psychopharmacologist who was already well known for other work. Roland Griffiths earned his doctorate in psychology at the University of Minnesota in 1972 and joined the Johns Hopkins University School of Medicine straight after; he was named research chief in 1975. Before psychedelics, his best-known research was on caffeine dependence, according to the Hopkins Medicine obituary.

The same release says Griffiths took up Siddha Yoga meditation in the 1990s and became curious about altered states of consciousness, which led him to psilocybin. The center’s own account names the people he worked with to launch the program: William Richards, Mary Cosimano and Robert Jesse (CPCR, Who We Are). The center dates the regulatory approval to restart this research to 2000.

The Good Friday Experiment, an earlier study of psilocybin and religious experience, has its own article in this journal.

What did the 2006 mystical-experience study do?

The 2006 paper in *Psychopharmacology* asked a narrow question: can psilocybin, given under comfortable and supportive conditions, produce experiences like spontaneous mystical experiences, and do they last? The volunteers were adults who had never used a hallucinogen and who took part regularly in religious or spiritual activities (Griffiths et al., 2006).

The design was double-blind. Thirty volunteers received psilocybin in one session and methylphenidate, a stimulant used as an active comparison, in another, in counterbalanced order. To obscure the design, six more volunteers received methylphenidate in their first two sessions and psilocybin, unblinded, in a third. Sessions were held one person at a time, two months apart, and community observers such as friends or family rated changes in each volunteer (Griffiths et al., 2006).

Psilocybin raised scores on mystical-experience questionnaires, and it also produced labile moods including anxiety. Two months later, volunteers rated the experience as having substantial personal meaning and spiritual significance (Griffiths et al., 2006). The journal printed the paper together with a discussion section of outside commentaries, which we did not read.

A follow-up at 14 months covered all 36 volunteers. 58% rated the session among the five most personally meaningful experiences of their lives, 67% among the five most spiritually significant, and 64% said it had increased their well-being or life satisfaction. Of the standard measures of personality, mood and quality of life, only a mystical-experience scale had changed from screening (Griffiths et al., 2008).

A 2011 dose-comparison study gave 18 adults five sessions each, including a placebo, in ascending or descending order. At the two highest doses, 39% of volunteers had extreme anxiety or fear at some point and 72% had a mystical-type experience; effects generally rose with dose (Griffiths et al., 2011). The same group reported a change in the personality trait of openness, which our creativity and openness article covers.

In 2008 the team also published safety guidelines for human hallucinogen research. They named overwhelming distress during the session as the most likely risk and prolonged psychosis as a rarer one, and set out safeguards: screening out people with a personal or family history of psychotic disorders, careful preparation, a safe room and at least two monitors (Johnson et al., 2008). The center says this paper guided review boards at other universities (CPCR, History). Our set and setting guide traces where those ideas came from.

How did the research move from volunteers to patients?

Smoking came first. A 2014 open-label pilot gave psilocybin within a 15-week smoking-cessation program to 15 psychiatrically healthy smokers. At six months, 12 of the 15 (80%) were abstinent on biomarker checks, but the authors wrote that the open-label design did not allow definitive conclusions (Johnson et al., 2014). At 12 months, 10 of them (67%) were confirmed abstinent, and 9 (60%) at a longer follow-up averaging 30 months (Johnson et al., 2017).

A randomized follow-on study was published in 2026. Its 82 smokers received either psilocybin or a nicotine patch, both with the same 13-week cognitive behavioral therapy program, and neither participants nor investigators were blinded. At six months, 17 of the psilocybin group (40.5%) and 4 of the patch group (10.0%) had biochemically verified prolonged abstinence, and no serious adverse events were attributed to either treatment (Johnson et al., 2026). The authors call it a pilot trial.

The cancer study followed. In a 2016 double-blind crossover trial, 566 people were screened by telephone, 56 were randomized and 51 completed at least one session; all had a potentially life-threatening cancer diagnosis. Everyone received a very low comparison dose and a high dose, five weeks apart, in random order, and instructions to participants and staff obscured which was which (Griffiths et al., 2016). About 80% still showed clinically significant decreases in depressed mood and anxiety at six months. The full results and their limits are in our end-of-life distress article.

Healthy-volunteer work continued alongside. A 2018 double-blind study randomized 75 people in three groups of 25 to a very low or high dose combined with a program of meditation and other spiritual practices, and measured lasting changes in attitudes and behavior six months later (Griffiths et al., 2018).

What is the Center for Psychedelic and Consciousness Research?

On 4 September 2019, Johns Hopkins Medicine announced that private donors had given $17 million to start the Center for Psychedelic and Consciousness Research. The release called it what is “believed to be the first such research center in the U.S.” and the largest of its kind, and said it relied on gifts because there was no federal funding for this kind of therapeutic research in people (Johns Hopkins Medicine, 2019).

The money came from the Steven & Alexandra Cohen Foundation and four individual philanthropists, and was to cover the first five years of operating costs, including six faculty and five postdoctoral scientists. Griffiths was named director. The planned patient studies covered opioid addiction, Alzheimer’s disease, PTSD, post-treatment Lyme disease syndrome, anorexia nervosa and alcohol use in people with major depression. By then, the release said, the group had published more than 60 peer-reviewed articles (Johns Hopkins Medicine, 2019).

Today the center describes itself as having more than 150 published studies and lists Frederick Barrett as its director (CPCR, Who We Are). For Canadian readers looking for comparable work at home, our Toronto clinical trials guide lists registered studies.

What did the Hopkins depression trial test?

The center’s best-known patient study was a depression trial run at Johns Hopkins Bayview Medical Center. It randomized 27 adults with major depressive disorder to start treatment right away (15) or after an eight-week wait (12); 24 completed it. Depression was scored by clinicians who did not know the group assignment, and the immediate group had much lower scores than the waiting group at the comparison points (Davis et al., 2021).

The authors listed the limits themselves. A waiting list controls for the passage of time, but not for preparation, rapport with the team or expectancy. The follow-up was short, the sample small and mostly White (22 of 24 completers), suicide risk was low by design, and some session facilitators had no formal clinical training (Davis et al., 2021).

A 12-month follow-up of the 24 completers reported response in 75% and remission in 58%, without a control group at that stage. Ratings of mystical experience predicted later well-being but did not predict improvement in depression (Gukasyan et al., 2022). How this trial compares with larger ones elsewhere is covered in our depression trials article.

What are the main criticisms of the Hopkins studies?

The first is blinding. Psilocybin’s effects are hard to miss, so participants can usually tell what they received. A 2021 review argued that psychedelic trials have generally not reported pre-trial expectations or whether blinding worked, and that their effect sizes are likely overestimated (Muthukumaraswamy et al., 2021). A 2022 review added that positive media coverage raises participants’ hopes, which makes these trials prone to large placebo and nocebo effects (Aday et al., 2022).

Hopkins researchers tried to reduce the problem. They used an active comparison drug in 2006 and very low doses in later trials, and in the cancer study gave instructions that hid the dose conditions from both participants and staff (Griffiths et al., 2016). Those authors also noted that such concealment may be hard to use where full disclosure of study arms is required. The depression trial and the 2026 smoking trial had no placebo at all.

The second is sample size and who took part. Most studies enrolled a few dozen people or fewer. The cancer trial’s authors wrote that their sample of 51, highly educated and predominantly White (94%), limits the generality of the conclusions (Griffiths et al., 2016). Volunteers in every study were screened for psychiatric and medical risk, so results may not apply to people who were excluded.

The third is the language of mysticism. Two researchers argued in 2021 that asking participants to fill in a mystical-experience questionnaire invites them to read their experience through that framework, and that the framework should be replaced by testable models (Sanders and Zijlmans, 2021). The 2022 depression follow-up, in which mystical ratings did not predict symptom change, is one data point in that debate (Gukasyan et al., 2022).

Roland Griffiths’ death and the center after him

Johns Hopkins Medicine announced on 18 October 2023 that Griffiths had died on Monday, 16 October, at age 77. He had been diagnosed with colon cancer in November 2021. The release credits his 2006 study with marking the beginning of a renaissance in psychedelic research, and describes a $24 million endowed professorship in his name, the largest ever at the School of Medicine (Johns Hopkins Medicine, 2023).

The same obituary notes that New York University and the University of California, Los Angeles began their own psychedelic research around the same time, with similar funding sources. The field Hopkins helped restart is now much wider than one team; our overview of what the research shows brings the main trials together.

What does this history mean in Canada?

Not a change in the law. Health Canada says the production, sale and possession of magic mushrooms are illegal in Canada, that there are no approved therapeutic products containing psilocybin in Canada or elsewhere, and that clinical trials are the most appropriate way to advance research with unapproved drugs such as psilocybin (Health Canada). Our psilocybin timeline places the Hopkins work beside Canadian events.

What we could not confirm

• The content of the commentaries printed with the 2006 paper. We read only the paper’s abstract and its bibliographic record.
• The live versions of the two Hopkins news releases. Their site refused our requests, so we read archived copies captured in 2019 and 2024.
• Whether participants in the healthy-volunteer studies guessed their condition. The abstracts we read do not report it.

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